This invention relates to an image reading apparatus for manually operating to scan a document to read an image therefrom.
Portable copiers serving as an image reader and recorder are currently being developed. Such portable copiers are typically formed with a window provided with a transparent member of glass or the like and the copier is manually moved over a document to be scanned with the window kept in contact with or near its surface such that image data received from the document are recorded on a sheet of thermal paper or the like. Recently, there have been many attempts to make such copiers smaller, lighter and thinner.
Since such a portable copier is intended to be operated manually for a scan, however, it tends to become unsteady when the user holds it with one hand to move it over the document to be scanned and if its window is moved away from the document surface, image data cannot be correctly received and there may appear black spots, for example, on the printed image. If the copier is made very thin, in particular, this problem can occur more frequently because the area of contact with the document becomes smaller accordingly.
Another problem associated with copiers of this type relates to dust and paper particles from the document, etc. which are easily deposited on the transparent member covering the window. Such deposited particles tend to produce unwanted shadows which are additionally received as image data to adversely affect the quality of the printed image. Previous attempts to clean such a transparent member included use of a bar with one end wrapped with cotton but such a procedure is troublesome and not very effective especially if the member is made of a soft plastic material because even a slight force thereon for cleaning may harm its surface.